Phonemes

I'm new at this...all apologies if this has been hashed to death.

The advice I have suggests trying to make up new sounds to create a
language.  This way, it says, you can avoid making too "Englishy".

I've tried using the charts of nasals, fricatives, dentals, etc and making
new sounds but they all end up sounding like L's or F's.  How did you guys
start the ball rolling?

Thank you for your help and a very entertaining listserv.

Dave